An iPhone Duo undergoing endurance testing has developed a weakening hinge after more than 451,000 folds, leaving its screen short of flat when the machine opens it. CNET identified the deterioration during a three-week test, although the handset remains functional and someone can still open it completely by hand.
The tested phone stops roughly 5 to 10 degrees before reaching its fully open position, while its hinge has lost the pronounced snapping sensation it originally produced. The display has neither cracked nor developed a more noticeable crease, and the phone continues to hold its other screen positions.
How the Hinge Changed
Lab director Matthew Murray traced the earliest changes to approximately 390,000 folds on Tuesday afternoon, using sensor readings alongside photographs and video collected throughout the experiment. The opening motion and required force changed gradually before the machine could no longer bring the screen completely open within its folding cycle.
Murray first noticed looseness during an afternoon livestream, when the opening sound became less firm, but the phone still reached flat when he left at 6 p.m. At approximately 440,300 folds, between 12:30 a.m. and 1 a.m. during the test, the screen stopped completing that movement before the machine began closing it again.
The Fold-a-Phone rig uses a wire to pull the handset open, and that wire had begun retracting before the display reached its final position. Initially, the screen continued moving the remaining distance on its own after the wire withdrew.
What Owners Can Take From It
The laboratory’s comparison puts the accumulated folding at nearly 12 and a half years when calculated at 100 folds each day. Apple has provided no public estimate for the iPhone Duo’s expected folding lifespan.
Separately, Apple acknowledged on October 26 that some iPhone Duo inner displays had a problem and directed affected owners to AppleCare for replacement. Apple said most handsets were not susceptible, affected devices appeared to develop symptoms soon after use, and there was no recall. Its hinge troubleshooting guidance provides no software remedy, with replacement of the inner display assembly specified when basic checks fail.
The endurance test will continue because the hinge wear has not triggered the laboratory’s stopping criteria: a power failure, a blackout, or sensors missing the required screen position within the allotted time. The test streams on weekdays between 1 p.m. and 5 p.m. ET while the lab waits for one of those conditions to be met.
